This critically important piece of your defense plan is far too seldom discussed, let alone practiced. You must identify the person against whom you may have to employ deadly force. The cost you pay for failure to do so can't be measured.

"I thought I had an intruder in my house. ... I shot the intruder, but the intruder was my wife." That was a 911 call in Florida a few years ago. The woman died. It's hard to imagine anything more heartbreaking than that, except possibly shooting your own child by mistake. Unfortunately, that happens, too. Sadly, the latest episode of a mistaken identity shooting occurred less than a month ago. They happen more frequently than we realize.

Rule Number 4 – Know your target and what is beyond it. That has been part of the training community's doctrine and dogma for decades. But, it's something most gunowners don't have to practice very much when they're shooting at the range. They buy a target, run it downrange, and enjoy shooting at it. But the controlled surroundings of either an indoor or outdoor range are very different from your home when you hear 'that bump in the middle of the night.' You're probably sleepy, it's dark, and who is downrange is unknown; that can be a terrifying set of circumstances.

We have to be absolutely sure of whom we even aim a gun at, and even more so if we make the decision to shoot. A flashlight should be just as much a part of your home defense equipment as your pistol. Keep your flashlight right next to the pistol. Don't pick up one without the other. There are lots of decent flashlights available at hardware stores and home improvement stores for less than ten dollars. That's one of the best investments in home defense you can make.

An indoor range is ideal for flashlight and gun practice. Even if you can see, have you ever shot with a flashlight in one hand and gun in the other?

Along with illumination, your voice is one of your most valuable tools. A simple 'Who's there?' would have prevented any number of tragedies I can name. If you want to be really 'tactical,' you can make your challenge from behind a position of cover. If you hear "It's me, Daddy" then it's time to stand-down.

Make sure you know where your family members are before you go hunting for Ninjas Coming From the Ceiling and then double check. In the incident that opened this article, the man thought he checked that his wife was still in bed. Obviously, he was wrong. Don't be in a hurry to go hunting unless you hear someone screaming. Make sure you're awake, too.

Remember, time is on your side, not a burglar's. If it is a burglar, you can afford to give him time to make a mistake. And you have the advantage of being on the defense. The military axiom is that an attacking force should be three times the size of the defense, that's how much of an advantage the defense has. You, on the other hand, can't afford to make a mistake in your own home. The odds are that it's a family member because they're there every night.

A light attached to the gun is not a light – it's a gun. Where the light goes, the muzzle goes. Watch that muzzle direction, keep it in the safest direction in your environment. Use bounce lighting from floor/ceiling to identify the threat.

The downside of this is that you have to learn to do several things at once. You have to hold a pistol in one hand, a flashlight in the other, and be able to speak while holding both. Learning how to do that while your knees are knocking at 3 a.m. is probably not the experience you're looking for. Even if you don't take any flashlight training, at least do a dry run of it occasionally. You don't even have to use your pistol for your dry run. Use your phone or any other object that you can carry with one hand. What you'll find is you have to figure out what to do with the flashlight while you're opening doors.

And guess what, if you do end up having to shoot in a real situation, you're going to end up doing it one handed because you're unlikely to drop the flashlight. Have you practiced your one hand shooting while holding something else in the other hand lately? Probably not. That's a good range drill for you next time.

Be awake, have a light, take your time, use your voice. Those are tactics that are more likely to save a loved one's life than your own.

Claude Werner is The Tactical Professor. He served in Airborne, Ranger, Special Forces and Mechanized Infantry units in the US Army as both an enlisted man and an officer. His military assignments include being a Special Forces A-Team Commander, Intelligence Officer, and Mechanized Infantry Company Commander. Well known in the shooting community, he was formerly the Chief Instructor of the elite Rogers Shooting School and has won six sanctioned IDPA Championships with snub nose revolvers. In his civilian career, he was Research Director of three commercial real estate firms and was the National Director of Real Estate Research for Deloitte & Touche LLP. His blog isTactical Professor.